HDFS-15041. Make MAX_LOCK_HOLD_MS and full queue size configurable. Contributed by zhuqi.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -290,6 +290,10 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
       = "dfs.namenode.blockreport.queue.size";
   public static final int    DFS_NAMENODE_BLOCKREPORT_QUEUE_SIZE_DEFAULT
       = 1024;
+  public static final String DFS_NAMENODE_BLOCKREPORT_MAX_LOCK_HOLD_TIME
+      = "dfs.namenode.blockreport.max.lock.hold.time";
+  public static final long
+      DFS_NAMENODE_BLOCKREPORT_MAX_LOCK_HOLD_TIME_DEFAULT = 4;
   @Deprecated
   public static final String  DFS_WEBHDFS_USER_PATTERN_KEY =
       HdfsClientConfigKeys.DFS_WEBHDFS_USER_PATTERN_KEY;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -393,6 +393,9 @@ public class BlockManager implements BlockStatsMXBean {
   // Max number of blocks to log info about during a block report.
   private final long maxNumBlocksToLog;
 
+  // Max write lock hold time for BlockReportProcessingThread(ms).
+  private final long maxLockHoldTime;
+
   /**
    * When running inside a Standby node, the node may receive block reports
    * from datanodes before receiving the corresponding namespace edits from
@@ -543,6 +546,10 @@ public class BlockManager implements BlockStatsMXBean {
     this.maxNumBlocksToLog =
         conf.getLong(DFSConfigKeys.DFS_MAX_NUM_BLOCKS_TO_LOG_KEY,
             DFSConfigKeys.DFS_MAX_NUM_BLOCKS_TO_LOG_DEFAULT);
+    this.maxLockHoldTime = conf.getTimeDuration(
+        DFSConfigKeys.DFS_NAMENODE_BLOCKREPORT_MAX_LOCK_HOLD_TIME,
+        DFSConfigKeys.DFS_NAMENODE_BLOCKREPORT_MAX_LOCK_HOLD_TIME_DEFAULT,
+        TimeUnit.MILLISECONDS);
     this.numBlocksPerIteration = conf.getInt(
         DFSConfigKeys.DFS_BLOCK_MISREPLICATION_PROCESSING_LIMIT,
         DFSConfigKeys.DFS_BLOCK_MISREPLICATION_PROCESSING_LIMIT_DEFAULT);
@@ -5159,7 +5166,6 @@ public class BlockManager implements BlockStatsMXBean {
   }
 
   private class BlockReportProcessingThread extends Thread {
-    private static final long MAX_LOCK_HOLD_MS = 4;
     private long lastFull = 0;
 
     private final BlockingQueue<Runnable> queue;
@@ -5195,7 +5201,7 @@ public class BlockManager implements BlockStatsMXBean {
             do {
               processed++;
               action.run();
-              if (Time.monotonicNow() - start > MAX_LOCK_HOLD_MS) {
+              if (Time.monotonicNow() - start > maxLockHoldTime) {
                 break;
               }
               action = queue.poll();

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -5736,6 +5736,14 @@
     </description>
   </property>
 
+  <property>
+    <name>dfs.namenode.blockreport.max.lock.hold.time</name>
+    <value>4</value>
+    <description>
+      The BlockReportProcessingThread max write lock hold time in ms.
+    </description>
+  </property>
+
   <property>
     <name>dfs.journalnode.edits.dir.perm</name>
     <value>700</value>